Initial read-only support for notes, style objects

[ludoo]

I added initial support for footnotes/endnotes parts, and footnotes/endnotes references. The new classes are read-only, much in the same way the styles part is, as I only need to read existing documents.

I also added a style class with id/type/name attributes, to ease working with documents where style ids are radically different from style names.

I could not wrap my head around your testing framework, so I added basic nose tests in the notes_tests folder.

[scanny]

Great @ludoo, thanks for this :)

[ludoo]

Added a few stuff after actually starting to use this library in a project I'm writing to convert from docx to latex/html/whatever. Main changes:

• accessing end/footnotes part properties return None if not relevant part is in the doc
• support more than one end/footnote reference in a single run
• add a method to cycle through run (textual) elements, and wrap them in classes

The last one is more a sketch than a useful implementation, but I really need something like this and doing it in the Run objects seems a more reusable solution.

[ZvikaZ]

Hi.
Is there a change to merge this pull request?
It'd be very helpful...
Thanks

[cassidylaidlaw]

Any idea when this PR will be merged?